Heater



Feb. 26, 1946.

H. J. DE N. MCCOLLUM HEATER Filed Oct. 6, 1943 lLlllllI Q? QW Wm. QQ wm, l M l NW NK QW@ QN d m Ww l\} NK ww. ww Q QN ,if N 1| WW Q NN Sm) n NN; .mi HKU Il l www N. w QD\\ -l Patented Feb. 26, 1946 `Henry ilBe EN. McCollumfzChicago, itl.; Thelma McCollum executrix of Said :Henry J. 53e .N.

4lificColliun, deceased Applicationfctbcr 6, 1943, ZSexiia'lNo. r5055115 n 13 Claims.

-My invention pertains tojheaters and `more particularly "to heaters oi the internal combustion type especially adapted `for, but not 'limited to,

`use .in heating Ventilating air supplied to 'aircraft cabins and other suitable spaces.

An object of r`my :invention is to provide anew and 'improved heater having lan Vexceedingly simple `and inexpensive control vfor 'automatically varying the heat output'of the heater in-accordance 'with the varying needs of lthe installation of Which'it forms a part. Y

.Other Vobjects and advantages will become apparent as the description proceeds.

*In the drawing:

Fig. v1 y-is a longitudinal, sectional view lci `a heater 'installation embodying one kfor-m of my invention; and y IFig. 2 is a simi-lar view L'o'f a dierent `heater installation 'embodying a second form -of my vinven'tiOn.

-In Fig. 1,'lI"-have illustrated -a "heater installation including a Ventilating air duct 1li@ whose Elefth-and -end Ais to be considered as connected -to a ram, blowe-r, or 4'other suitable source of :supply .of Ventilating fair. The rirghthand -end iof :the Ventilating .air .duct may 'lead Adirectly l'to ian :aircraft cabin or other vspace :to he heated, or may communicate therewith-through anysuitable duct arrangement having c-ne or more outlets, as desired. The Ventilating air .flowing through .the `duct :Ill `.passes over la `heater :comprising :a combustion chamber I2 .and #a heat-ex- -changer fl il. The .combustion chamber .i 2 may ibe .provided with `the `usual electrical Ligniter, l not shown, .and lthe 'heat exchanger may 4be .of any usual -or Vsuitable construction. "The 'products -o'f `combustion 'formed in the combustion .chamber i2 Vpass into .the heat exchanger Ill :and are :discharged through 1an exhaust ipipe 115.

The combustion chamber :I2 `is providedwithra combusti-ble mixture fof ffnel Aand lair through an induction -tube t8 which connects 1the combustion `chamber I2 with a carburetor '20 of any :convventional lor-suitabletype. This carburetor :may he Vsupplied with gasoline or other Aifuel from .any :suitable source. The duct Illpis providediwitha suitable opening receiving the :inlet ,end nf :a Vcombustion -air pipe-,2:2 having .a longitudinal rsection 24 extending .lengthwise :of .the heater through the combustion chamber fi' vandhe'at exchanger IA. This .longitudinal -section .-24 is con-- nected .to the vcarburetor y2&1 by ia laterally extending -section 25 ,and a Afurther .section .128which is located exteriorly of the duct LQ.

,-Air .is circulated through .the -.combnstion .air

supply pipe, carburetor, linduction pipe, combusition chamber, 'heat exchanger, and exhaust Pipe, either *by creating a pressure 'by 'means of "a .ram or v-Ioilower connectedto the inlet end ofthe 'combustion air supply k'pipe 22, or by creating suction at the outlet of the exhaust jpipe I6, or by acom- 'binatio-n of both. The Vrate of `iloW Aof jthis VAcombustion air is regulated by a butterfly valve 3B controlled by -a ytemperature 4responsive bellows or sylphon l32 `mounted yon a rod 34 extending through a wall of -a 'portion oi the combustion -air supply pipe and terminating in Ja 1threaded end and engaged byan adjusting lnut 33. The nut canbe manuallyset vto provide any desi-red `posit-ion of the Valve "30 ffor, 'any given'temperature `of :the combustion air lilowing yaround the bellows T32. For any-given 'setting of the nut 38, accurate flow of the control of combustion "air -is automaticallyiestalol-ished by `contraction orex- `pension ci 'the r`bellows 132 in accordance with temperature variations :olf the combustion *air 'itlowing over this'bellows. Since the fuel-delivered thereore, theheat output zoll Vthe heater.

:normal operation, combustion air `entering '1t-he pipe '22 flows through 'the lcen-tero'f the combnstion chamber I2 :and heat exchanger M and :absorbs heat therefrom. "This `combustion air then passes `i-nto- .the laterally yextending portion i216 of nthe combustion air pipe containing the temperature responsive "bellows 132'. This Aportion of the combustion air pipe is exposed to lthe ven- `rilatinglairleaving-the heat exchanger |14. When Y:the combustion air is'heated to too high fa Item p-,eratura :thebel-lows 132 expands ,and vreduces ithe flower :combustion air, therelcny reducing the iheat loutputof the heater. Qn tthe other handwhen A`the :combustion .air iis insuiciently heated, the bellows 32 contracts and `permitsvzmore combustion air to ow to the heater to thereby :increase .the heat -fo-utput thereof. In Athis manner, the

@5 Fheater fis effectively controlled :to deliver eat all :timos :a lquantitypf .heat 'proportion-alto the then existing needs of vthefinstallation..

In Eig. l2, I have illustrated-a `second form .my :invention comprising a yentilating -air minet `Alfil @noiosi-nga heater :having a icom-bustion cham- .ber 42.and heat eicchanger 44. combustible Imixture iis delivered to #the ycoznlmstion chamher A2 through aan Aindi-lotion :pi-pe :4 6 connected @to .a carlouretor '48 :supplied .combustion ifair a rod 58 connecting this valvewith a temperatureresponsive bellows or Sylphon 60 mounted in a housing 62 located in the duct 40 and attached to the rear wall of the portion 56 of the combustion air supply pipe. The bellows 60 is supported at one end on a lever E4 pivotally mounted on a pin 66 carriedby a wall oi the duct 40. The other end of the lever 64 is 4pivotally connected to a collar 68 for movement therewith. This collar is swivelled'on the end of a screw 10 which threadedly engages a post I2` attached to a wall s of the duct 40 and which may be'adjusted to provide any desired initial setting of the valve 54.

p In .this form of my invention the automatic temperature control for the valve 54 is diierentially Vresponsive t0 the temperature of the lVentilating air leaving the heater and to the temperature of the Ventilating air supplied to Ythis heater. Since the latter temperature is the same as the temperature of the combustion air entering the inlet 52 of the combustion air supply pipe 50, the automatic temperature control is also differentially responsive to the temperature of the Ventilating air leaving the heater and the temperature of the combustion air entering. the

combustion air supply pipe. This differential control is effected by providing the housing 62 with the particular arrangement of inlet and out.

let means which I shall now describe.

As clearly shown in this Fig. 2, the housing 60 has an inclinedA inlet 14 which connects the interior of the housing with the interior of the Ventilating air duct 4B adjacent to and down,

stream from the righthand end of the heat exchanger 44. Air is also supplied to the housing 62 by a pipe 'l5 having its inlet end 18 located inthe duct 40 upstream of the heater. Except for its inlet and outlet ends, the pipe 16 is located externally of the duct 4B so that the air exchanger 44 and are ultimately discharged to atmosphere through the exhaust pipe 82 after giving up their heat to the walls of the combustion chamber and heat exchanger.

Ventilating air ilows over the combustion chamber 42 and heat exchanger 44, absorbing heat Y therefor and then passes to the aircraft cabin delivered to the housing 60 through this pipe is at the same temperature as the Ventilating and combustion air delivered to the lefthand end of the heater.

In the housing 62, the heated Ventilating air supplied through inlet 14 mixes with the cool air delivered by the pipe 15 and this admixture flows over the bellows to determine the position of the valve 54. This admixture then passes through the housing outlet 80 and mixesl with the ventilating air sup-plied to the aircraft cabin or other space or spaces.

In the operation of that embodiment of my invention shown` in Fig. 2, a singleram or blower may supply both the Ventilating and combustion air. The combustion air passes into the inlet end "52 of the combustion air pipe and absorbs heat from the combustion chamber 42 and heat exchanger 44. This air then passes to carburetor 48 where it is mixed with fuel and the. combustible mixture formed by this carburetor is then delivered to the combustion chamber 42. The

' combustion occurring in Athis chamber creates hot products of combustion which flow into the heat the valve control bellows 60 will be affected both by the temperature of the air delivered t0 the heater and by the temperature of the Ventilating air leaving this heater. When the heater is iirst started, the Ventilating air leaving the heater will be at the same temperature as that delivered to the heater, so that the maximum quantity of combustible mixture would ordinarily be delivered to the heater when it is i'lrst started. After the heater has attained normal operating temperature, the Ventilating air leaving the heater has had its temperature raised by passing over the heater and this increase in the temperature of the Ventilating air will tend to expand the bellows 60 and restrict the air flow to the carburetor 48.

On the other hand, if the air delivered to the n heater is extremely cold, the low temperature of the air delivered to the housing 62 through pipe 'l5 may prevent expansion of the bellows 60 and maintain the maximum heater operation. This dilerential control of the throttle valve for the combustion air is more sensitive than the control shown in Fig. l and is the preferred form of my invention.

It is to be understood that my invention is not limited to the particular details shown and described herein, but may assume numerous other forms and that my invention includes all other modiiications, Variations and equivalents coming within the following claims.

I claim:

1. Apparatus of the class described, comprising a Ventilating air duct, a heater comprising means forming a combustion chamber and heat exchanger located in said duct, a carburetor for supplying combustible mixture to said combustion chamber, an air supply pipe for said carburetor extending through said combustion chamber and heat exchanger, a valve for controlling flow through said pipe, a temperature responsive means in said pipe between said heat exchanger and carburetor, and a connection between said last named means and said valve.

2. Apparatus oi the class described, comprising a Ventilating air duct, means forming a combustion chamber located in said duct, a heat exchanger receiving products of combustion 'from said combustion chamber and located in said duct, a carburetor for supplying a combustible mixture to saidcombustion chamber, a separate source of air supply for said carburetor, means for pre-heating the air supply to said carburetor, a valve controlling air ilow to said carburetor, and temperature responsive control means for said Valve located in said duct downstream of said heat exchanger.

.3. A heater of the class described, comprising means forming a combustion chamber, a heat exchanger receiving hot products of combustion from said chamber, a carburetor for supplying a combustible mixture to said combustion chamber, an air supply pipe for said carburetor extending through said combustion chamber and heat exchanger, means for regulating the flow of air through said pipe to said carburetor, and temperature responsive means in said pipe for controlling said last-named means.

4. A heater of the class described, comprising means forming a combustion chamber, a heat exchanger receiving hot products of combustion from said chamber, a carburetor for supplying a combustible mixture to said combustion chamber, an air supply pipe for said carburetor extending through said combustion chamber and heat exchanger, means for regulating the ilow of air through said pipe to said carburetor, temperature responsive means in said pipe for controlling said last-namd means, and a manual adjustment for said temperature control means.

5. Heating apparatus of the class described, comprising a Ventilating air duct, means forming a combustion chamber located in said duct, a heat exchanger located in said duct and receiving hot products of combustion from said combustion chamber, a carburetor for supplying a combustible mixture to said combustion chamber, an air supply pipe for said carburetor, and means dii- 30 ierentially responsive to air temperatures in said duct on opposite sides of said heat exchanger for Variably regulating air fiow to said carburetor.

6. Heating apparatus of the class described, comprising a Ventilating air duct, means forming a combustion chamber and heat exchanger located therein, a carburetor for supplying combustible mixture to said combustion chamber, aU combustion air pipe for said carburetor extending through said combustion chamber and heat 40 exchanger and communicating with the interior of said duct upstream of said combustion chamber, a throttle Valve for controlling flow through said pipe to said carburetor, a temperature re- 4- sponsive bellows for Variably positioning said Valve, a housing enclosing said bellows, means for supplying the interior of said housing with heated Ventilating air, means for supplying the interior of said housing with unheated Ventilating air, and means for manually positioning said bellows and Valve.

'7. Apparatus of the class described, comprising a heater having a combustion chamber and heat exchanger, a carburetor for supplying combustible mixture to said combustion chamber, an air supply pipe for said carburetor extending through said combustion chamber and heat exchanger, a Valve for controlling ow through said pipe, a temperature responsive means in said pipe between said heat exchanger and carburetor, and a connection between said last named means and said Valve.

8. Apparatus of the class described, comprising a Ventilating air duct, means forming a combustion chamber located in said duct, a carburetor for supplying a combustible mixture to said combustion chamber, a separate source of air supply for said carburetor, means for pre-heating the air supply to said carburetor, a valve controlling air flow to said carburetor, and temperature responsive control means for said Valve located in said duct downstream of said combustion chamber.

9. A heater of the class described, comprising means forming a combustion chamber, a heat exchanger receiving hot products of combustion from said chamber, a carburetor for supplying a combustible mixture to said combustion chamber, an air supply pipe for said carburetor extending through said heat exchanger, means for regulating the flow of air through said pipe to said carburetor, and temperature responsive means in said pipe for controlling said last-named means.

10. A heater of the class described, comprising means forming a combustion chamber, a heat exchanger receiving hot products of combustion from said chamber, a carburetor for supplying a combustible mixture to said combustion chamber, an air supply pipe for said carburetor extending through said combustion chamber, means for regulating the flow of air through said pipe to said carburetor, temperature responsive means in said pipe for controlling said last-named means, and a manual adjustment for said temperature control means.

.11. Heating apparatus of the class described, comprising a Ventilating air duct, means forming a combustion chamber, a heat exchanger located in said duct and receiving hot products of combustion from said combustion chamber, a carburetor for supplying a combustible mixture to said combustion chamber, an air supply pipe for said carburetor,l and means located in said duct and diierentially responsive to air temperature in ,said duct on opposite sides of said heat exchanger valve, a housing enclosing said bellows, means for supplying the interior of said housing with heated Ventilating air, and means for supplying the interior of said housing with' unheated Ventilating a1r.

13. A heater of the class described comprising a Ventilating air duct, means forming a combustion chamber located in said duct, a heat exchanger located in said duct and receiving hot products of combustion from said combustion chamber, a carburetor for supplying a combustible mixture to said combustion chamber, an air supply pipe for said carburetor extending through said combustion chamber and h'eat exchanger, a Valve in said pipe for regulating the flow of preheated air through said pipe to said carburetor, a bellows for controlling said Valve in response to temperature Variations, and a manual adjustment for said bellows and Valve.

HENRY J. DE N. MCCOLLUM. 

